EP-A-286,545 describes a book holder including a flexible backing strip formed to extend along the covers of an open book with ends bent back toward each other to overlap the pages of an open book.
CH-A-593,150 discloses a flat bookmarker with a twistable hook-like end arranged to engage and hold several pages.
GB-A-1,410,019 describes a bookholder and stand which has a back having flat members to clamp the open cover of a book, and a "fence" or rim along the front to restrain the lower parts of the open pages.
Several older patents describe bookmarkers made of wire bent into more-or-less practical and complex shapes. For example, U.S. Pat. No. 1,710,949 describes a braced spring clip of bent wire which clips over open pages and has a projecting page-engaging arm. U.S. Pat. No 2,661,568 discloses a bookholder made of bent spring loops which clip over the top of the book cover, with projections forming an easel on which the book rests. U.S. Pat. No. 4,382,617 describes a combined book leaf holder and bookmark made of a bent wire with a backing loop which engages between the spine of a book, and lateral bent prongs which clip against the facing pages.
WO 88/07451 relates to a page fixing device having two spaced-apart prongs opposite a flat upper face. This device slides over the facing open pages of a book, with the upper face laying on top of the pages and the prongs engaging behind the pages, on either side of the opened book.
These prior book holders and page markers have not found general market favor due to their complex designs, liability to breakage, inconvenience of fitting or removing them, size, material and/or other reasons; such as the risk of ripping pages when the device is placed on a book or removed. Despite attempts for many years, so far there is on the market no satisfactory mass merchandisable book clasping and page marking device which meets the criteria of simplicity of manufacture, inexpensive and easy-to-handle material, robustness, and its convenience and effectiveness of use.